The present invention generally relates to semiconductor integrated circuits and a method of fabrication thereof. The present invention relates more specifically to a back end of line (BEOL) thin film resistor and methods of fabricating the same.
Recently, doped polysilicon resistors have been replaced with single thin film resistors that are formed of a material that has a higher resistivity than that of polysilicon. Examples of such higher resistivity materials include, but are not limited to titanium nitride and tantalum nitride. Integrated circuits including these resistors require the fabrication of vias having different heights, e.g., vias that land on the resistor and regular vias that land on an underlying metal to form the metal interconnect, which imposes integration challenges.